Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the return shape (URL, dimensions, caption, credited people), which is helpful context, but says nothing about pagination, ordering, or behavior when the type filter matches nothing.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, zero waste, front-loaded with the resource identity before the filtering instruction. Nothing needs trimming.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With a full output schema and 100% parameter coverage, the description does not need to explain return values or param formats, and it correctly delegates the accepted type values to imdb_image_types. It is nearly complete, missing only explicit sibling routing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the schema already documents id, url, type, and limit thoroughly, including the enum-like type values. The description's only added value is redirecting to imdb_image_types for accepted values, which is marginal against a fully documented schema – baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific verb+resource ('IMDb title media index: image metadata') and enumerates the returned fields (image URL, dimensions, caption, credited people). The 'title' scope cleanly separates it from the sibling imdb_name_images and imdb_name_videos.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives one concrete usage instruction ('Filter with type; call imdb_image_types for the accepted values'), which is genuinely useful routing. However, it never states when to prefer this over siblings like imdb_title or imdb_title_videos, so the when-to-use guidance is only implied.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.